Why did mammals evolve before birds

Animal species overview

There are countless different animal species on our earth. We present many of these different animals to you in the JUNIOR animal lexicon. So that you know the difference between mammals and mollusks, for example, we explain the essential terms to you here. (Photos: Fotolia and Panthermedia)

Back to the JUNIOR animal lexicon for children!

What are mammals

Mammals are animals that have a spine (Vertebrates) and their body temperature remains the same. Most mammals have hair and give birth to live young. These are first suckled with breast milk, where the Term "mammals" derives. The first mammals lived in the world as early as 200 million years ago. Today there are around 5,400 species of mammals. Of all animal species, mammals are the most developed. Most of all that Mammalian brain has developed strongly.

What are amphibians?

Amphibians also belong to the Vertebrates, because they too have a spine. They evolved from fish around 400 to 360 million years ago. Are amphibians cold-blooded animals. This means that their body temperature fluctuates. Its name comes from the Greek and means something like "double-lived"because they can live both in water and on land. A total of around 7,000 different amphibian species live on earth.

What are invertebrates?

The term "Invertebrates" denotes animal species that no spine or have no skeleton and therefore also Molluscs to be named. Most invertebrates have one Rasping tongue with which you can grate and chop. There are approximately 130,000 species of invertebrates on earth.

What are insects

insects belong to the invertebrate species and also to the Arthropods. Instead of a skeleton inside the body, insects have one Exoskeleton. They evolved over 400 million years ago and many species live solitary. From the larval stage to the adult animal, insects perform a so-called Metamorphosis. There are approximately 1 million species of insects in the world.

What are birds

Birds also have a constant body temperature and a spine, which is why they, like mammals, to the Vertebrates counting. Birds evolved from dinosaurs about 150 million years ago. Instead of the fur, birds own feathers with which most species of birds can also fly. You have tough Beaks and claws on the feet. Their young hatch from eggs and are not suckled. Today there are around 9,000 species of birds in the world.

What are reptiles

Reptiles are among the Vertebrates and have a fluctuating body temperature. They have lived on earth for over 315 million years and evolved from amphibians. The designation "Retiles" is derived from Latin and means "creeping". Reptiles have horn scales and hatch from eggs. There are around 9,800 species of reptiles on earth today.

What are fish

fishes evolved from unicellular organisms about 450 million years ago and are those oldest vertebrates of the world. They breathe through gills and have no lungs. Fish lay eggs and only live in water. Your body temperature depends on your environment. In the case of fish, between Cartilage and bony fish differentiated. The skeleton of the cartilaginous fish is made up of cartilage and their skin is made up of tiny teeth. In addition, they do not have a swim bladder, so they always have to swim to be able to maintain a height. Bony fish have a skeleton made of bones and their skin is made up of scales. They have a swim bladder.

What are spiders?

Arachnids are invertebrates arthropod and differ from insects in that they are always eight legs to have. The body of arachnids is usually made up of a front and back abdomen. This species has lived on earth for 500 million years. There are over 100,000 species of arachnid in the world. They don't just belong be crazy, but also Scorpions, ticks and Mites.